The invention relates to a semiconductor optical receiver device, a optical receiver module and a method for manufacturing semiconductor optical receiver device, specifically, pertaining to the semiconductor optical receiver device that is particularly provided with a buried mesa-structure and whose response speed improves, the optical receiver module and the method of producing such semiconductor optical receiver device.
The production steps of a backside-illuminated type Avalanche Photo Diode (APD) are disclosed in FIGS. 1 through 9 of Japanese Patent Application Laid-open No. 2004-179404. In turn, in FIGS. 11 through 18, the production steps of a surface-illuminated type APD are disclosed. To note, the surface-illuminated type APD shown in FIG. 18 adopts a p-type ring electrode while a contact portion (through hole) with the p-type electrode of the backside-illuminated type APD shown in FIG. 9 is not of ring shape. However, even with such backside-illuminated type APD as mentioned above, nowadays, it is general to form the through hole of the passivation layer in contact with the p-type electrode into an annular shape and form a mirror inside the through hole, which mirror is formed by the passivation layer inside the through hole in contact with the metallized electrode, so that light reflected from the mirror can be reabsorbed.
Further, a basic technology of APD provided with a field control layer is disclosed in Japanese Patent Application Laid-open No. 2002-324911.
According to either the backside-illuminated type APD or the surface-illuminated type APD disclosed in the above prior arts, the outer diameter of the mirror or the diameter of the light receiving portion thereof is smaller than the diameter of the inner first mesa. On the other hand, it is necessary to reduce parasitic capacitance in order to improve on the response speed of the APD. In order to reduce the parasitic capacitance, it is required to reduce the diameter of the first mesa. However, the reduction of the outer diameter of the backside-illuminated type APD mirror or the diameter of the light receiving portion of the surface-illuminated type APD causes the light receiving sensitivity of the photodiode or the optical coupling tolerance with optical fibers to deteriorate.